Electron discharge device



p 1946. G. R. KILGORE ET AL 2,407,708

ELECTRON DI SCHARGE DEVICE Filed April 24', 1942 2 Sheets-Sheet l Q 75: 2 7 I Y 2/ k 9= 27 32 J 21 mp INVENT R Sept. 17, 1946. G. R. K1LGQRE ET All 4 V ELECTRON DISCHARGE DEVICE Filed April 24, 1942 2 Sheets-Sheet 2 INVENTORS fiw ATTORNEY Patented Sept. 17, 1946 UNITED STATES or-rice ELECTRON DISCHARGE DEVICE George Ross .Kil'gore, Verona, .andLouis .Malter, .Newark, N. J assignors to Radio'Corporation-of America, a'corporation' ofv Delaware Application April '24, 1942 Serial*No.4i40,300

19 Claims. 1

Our invention relates to electron dischargedevices, more particularly to such devices utilizing electron beam deflection and useful at-ultra high frequencies.

In conventional tubes utilizing beam deflection, a beam of electrons is directed from the cathode toward and between a pair of deflecting electrodes toward an apertured electrode behind which is placed an electron collector. Alternating radio frequency voltages are applied to the deflecting electrodes to cause the electron beam to be deflected across the aperture in the apertured electrode to thus control the amount of current to the collector, which may be used as an output elect-rode. In such types-of tubes the'de- 'flection-sensitivity drops 01f as the frequency at whichth tub is operated is increased. Efforts have-been made to increase the deflection sensitivity or the transconductance of the tube, but such efforts have not met with agreatdeal or success. Conventional tubes of this kind :are also subject to the limitation that'when operated at ultrahigh frequencies the input circuit tends to be of low resonant impedance resulting in an excessive amount of power being required to drive the tube. This decreases the effective powergain of the'tube when operated asan amplifier.

Fundamental causes of low resonant impedance include among other things radiation :and resistance losses. I It is an object of our invention :to .provide an electron discharge device of the beam deflection type which is particularly suitable for use-at high frequencies and which has .a comparativelyhigh transconductance.

It is another object of our invention toprovide such a device utilizing an input circuit having high resonant impedance, thus making more effective use of the driving power.

A still further objectof our invention is to provide an electron discharge device :of thebeamdeflection type usefulat ultra high frequencies and which employs novel low loss input and .output electrode systems and circuits.

A further object of ourinvention is -.to provide such .a device :in which undesired coupling, due to common leads and inefiective shieldingiis reduced to a minimum.

Another object of our invention .is tox-provide an electron discharge device of the beam ,deflection type useful at ultra high frequencies as an amplifier, oscillator oramixer.

The novel features which w :believe *to be characteristic of our invention are set forthwith particularity in the appended claims, but themvention itself will best be understoodby reference to thefollowing description taken in connection with the accompanying drawings in whichiFigure '1 is a longitudinal section of an electron .discharge device made according to our invention, Figure 2 is a section taken along the lin -2--2 of Figure '1, Figure 3 is a partial longitudinal section of the device shown in .Figure 1 turned on its longitudinal axis, Figure 4 is a fragmentary perspective showing details of construction of the deflectingelectrodes tFigure :5 is a schematic section of the tube shownin Figure 1 and its associatedcircuit, Figure 6. is .a schematic longitudinal sectiono'f a modification of an .electron discharge device made according "to our invention utilized as anamplifieror oscillator, Figure 7 is a schematic longitudinal section of a. still further modification of the electron discharge device shown in Figure 1 audits associated circuit, Figure '8 is :a schematic longitudinal. section of a still further modificationof anelectron discharge device made according-to our invention, :and Figure '9 is apartial perspective :in section showing details of construction .of Figure 8.

Referring to the drawings, .an electron discharge devic :made according to our invention comprises an :evacuated envelope I0 having the usual press H and base P2. Supported from the basezis the indirectly :heated cathode l3, having a lead 13'. .Adjacent;the cathode is positioned the apertured beam forming and focusing electrode tank circuit or cavity resonator comprising portions .2;3-.and 2.4';provided with apertures 23' and .24. Positioned between the member 2| and the portion .23 pf the resonant cavity are the beam directing electrode elements -22 supported by 'means of the glass bead construction 22' and having leads 22" extending through the wall of the envelope l0.

As bes'tshown in 'Fi uresLB and beam deflecting plates 25:and;2'| are positionedadjacent-the apertures and electricallyconnected' to .and sup- "portediby opposite .wa'lls 0f the resonant cavity,

- tures.

The resonant cavity, as shown in Figure 3, is provided with a pair of apertures from around which extend the tubular extensions 28 and 29 and into which reentrant envelope wells 28 and 29 extend for receiving elements to be described. Supported from and between the tubular members 28 and 29 is the apertured electrode element 30 having aperture 3| and positioned centrally of the apertur th conducting element or Wire 32 for providing a double aperture for the purpose ofobtaining the desired output voltage-current characteristic.

Extending within the reentrant portion 2.8 is a coaxial transmission line 33 provided with coupling loop 34 for introducing the signal or control voltage for energizing the resonant cavity. Tuning plunger 35 provided with insulating adjusting handle 36 is mounted to slide within the other reentrant portion 29' within the cavity for bringing about tuning of the resonant cavity.

In Figure 5 is shown the schematic longitudinal section of the tube shown in Figures 1 to 4 inclusive and its associated circuits. Voltage sources 3'! and 38 are provided for supplying the necessary biasing voltages to the beam directing electrodes 22 and for supplying the proper positive accelerating voltages to the cavity resonator or resonant cavity tank circuit 23-24 and collector l1. In operation, if the device is to be used. as a mixer or oscillator, the oscillator voltage may b applied to the beam directing electrodes 22 as indicated, and the controlling or input signal voltage means of the coaxial line cable 33 to the resonant cavity tank circuit. Thus the beam has applied to it the two alternating voltages of high frequency for producing the intermediate frequency voltage in the output system which may be connected between the collector I! and the resonant cavity tank circuit. The output circuit includes the primary of transformer 39 and by-passing condenser 40. If desired the electrode l1 maybe coated with secondary emitting material and the secondaries collected by the electrode 30.

In operation a beam of electrons generated by cathode l3 and formed and focused into a beam by beam forming member [5 pass through apertured elements 20 and 2| between the electrodes 22. If th tube is used as the oscillator control electrodes the'oscillator voltage is applied to the leads 22' connected to these two electrodes. The deflected beam then passes between the deflecting elements 26 and 21 of the resonant cavity tank circuit, Inasmuch as one mode of operation involves the flow of radio frequency current from one aperture radially and outwardly along the inner wall of the resonator and inwardly along theother inner wall to the other aperture,

-an alternating voltage differential appears between the apertures, and hence deflecting electrodes connected to opposite walls of the cavity at the apertures will provide a transverse deflecting field therebetween. Since these elements 26 and 2'! act to shield the beam from the enclosed field within the resonant cavity, the beam is subject substantially to only the transverse field between the deflecting electrode elements 26 and 21 Only transverse deflection of the beam will, therefore, result and substantially no velocity modulation of the beam will take place which latter action is the usual operation which takes ture 3! of element 30 and collected by means of This beam is deflected across the aper-.

4 V the collector II. The output current is taken from between the collector l1 and the electrode 30. The input voltage is fed into the coaxial line, and the electromagnetic field of the loop 34 coupled with the interior of the resonant cavity sets up an electromagnetic field which will energize the resonant cavity in the desired manner to bring about voltage difierentials between opposite walls of the cavity at the apertures so that deflection will result. By moving the tuning plunger-in and out, the frequency of oscillation of the resonant cavity may be adjusted within limits. It is, of course, also possible to apply both the oscillator and signal voltage to the coaxial line, and use electrodes 22 only for initially arrangement we provide an evacuated envelope 50 having at one end thereof the cathode 5| and an apertured beam forming and focusing electrode 52, the electron beam being eventually collected by collector. 53 at the other end of the envelope. In this arrangement, positioned between the cathode and collector is a double resonant cavity tank circuit or cavity resonator system for first deflecting the electrons across an apertured electrode and for inductively abstracting energy from the deflected beam. This arrangement comprise tubular member 54 having the successive apertured elements 55 and 56 with the apertures in alignment with the aperture in the beam focusing element 55. The electrodes 51 and 58 direct th beam into the resonator 59. Tubular member 54 is electrically connected to the resonant cavity tank circuit 59 having deflecting electrodes 60 and BI connected in the manner shown in Figure 3. Positioned intermediate this resonantcavity and the output resonant cavity tank circuit 66 is an apertured electrode 65 across the aperture of which the beam is initially deflected. Current not intercepted passes through the apertures 6'l68 in the resonant cavity. tank circuit or resonator 63 andinduces an alternating voltage within the resonator to energize the resonator in a manner now well understood.

The envelope is provided with a plurality of reentrant portions extending through apertures that is the input circuit from the output circuit.

If, however, it is desired to use the device as an oscillator, coupling link 12 may be placed in position so as to feed energy back from the interior of the output resonant cavity tank circuit 66 to -the interior of the input cavity tank circuit 59.

If desired this coupling link can be made so that its electrical length can be changed so that energy is -fed back into the input circuit in proper "phase.

The voltage divider arrangement 13 permits proper biasing voltage to be applied to the beam .directing electrodes 51 and'58 and the voltage source 74 provides the various positive voltages which are to be applied to the resonant cavity E tank circuits, the collector and the apertured intermediate electrode;65. f

In Figure 7 is shown a still further modification of our invention utilized as a mixer if desired and in which the function'of the beam-directing electrodes 51 and 58 is taken over by the resonant cavity itself.

In this arrangement the evacuated --envelope 80 has at one end thereof the cathode 8!, beam forming and focusing 'apertured electrode 82, and at the "other end "acollector 83. Positioned between the cathode and collector is the beam'defleeting arrangement comprising the tubular element B-d having the apertured discs or partitions 85 and 86. 'The resonant cavity tankcircuitis formed in two parts 81 and 8 8 insulated from each other by means of insulating ring 139 which may 'be mica, thus permitting different direct volt'ages'to be applied to the two halves of the cavity by providing a closed hollow tank circuit for confining the radio frequency field. Thus'the deflector elements 93 "and 91 connected to the opposite walls of the resonant cavity may (have applied thereto difierent voltages for properly centering the beam onthe aperture d3 of element '92, divided to provide a double aperture by means of rod 94. The input voltage may be applied by means of the coupling loop 91 and a second loop 98 may be utilized, for example, for applying a local oscillator voltage although a tuning plunger might be used in this case also as in Figure 5. Again the output voltage is taken between collector83 and the part 880i therescnant cavity tank circuit by means of the transformer ltl andby-passing condenser m2. Voltage source 100 provides the necessary biasing voltages and divider arrangement "99 permits proper biasing voltages to be applied to deflecting elements 90 and 9!.

In Figures 8 and 9 is shown amodification of the device shown in Figure 5 and utilizing deflecting elements for bringing about successive additive deflection. The envelope H contains the cathode I06, the beam formingelectrode I'M and collector N38. The beam deflecting means comprises tubular-member I89 having transverse 'aperturedpartitions Hi1 and HI and contacting the wall of the resonator 114 between which and the apertured partition iii are positioned the beam directing electrodes 1- i 2 and-H 3. The resonator l [4 is provided with apertures surrounded by "tubular extensions M5 and llfi for'receiving the usual coupling loops. An apertured plate member H1 provided WithI'Od MB for providing a double aperture is positioned between tubular extensions H5 and H6.

In accordance with our invention the deflecting electrodes HS and R3 are provided with a plurality of successive slots forming a plurality of successive deflecting elements 119' and 1211', the distancebetween the centers of the elements being equalto the distance travelledby an electron -during a period of the applied controlling voltage. Thus-the electrons will be successively and additively deflected in the same direction in passing through the resonator H4, thus increasing'the transconductance or the deflecting sensitivity of the tube.

While we have indicated the preferred embodiments ofour invention of which we Jare now aware and have also indicated onlyone specific tions may bemade in the particular structure used and the purpos for which it is employed without r departing from the scope of our inventlon asset forth in the appended claims.

Whatwe claimas new is:

1. An electron discharge device'having a-cathodemeans for'providinga beam o'f electrons' and a collector for receiving said beam of electrons, and means positioned between the cathodemeans and collector and including a hollow'resonant conducting member extending transversely-of the path ofthe beam between the cathode meansand the collector and having opposed apertures Sinopposite walls thereof through which the beam is directed during operation of 'said electron dis charge device, and a pair of deflecting elements within said 'hollow resonant conducting member each of which isseparate from and extending transversely of the wall of said hollow resonant conducting member and is electrically connected to an oppositewallof the hollow resonant conducting member next adjacent an aperture lfror deflecting the'beam of electrons in its passage through the hollow conducting member, another portionof the wall of the hollow resonant-conducting member 'having an aperture adapted .to receive means for coupling the hollow resonant conducting member to an input circuit, 'andlanother portion of the wallof the hollow resonant conducting member having another aperture adapted to receive a tuning plunger for controlling the resonant frequency of the hollow :resonant conducting member.

2. An electron discharge devicehaving acathode means for providing a beam of electrons and a collector for receiving said beam of electrons, and means positioned between the cathodemeans and collector and including a hollow resonant conducting-member extending transversely of the path of the beam-between the cathodemean and the collector and having opposed apertures in oppositewalls thereof through which the beamis directed during operation of said electron discharge device, and a pair of deflecting elements within and separate from the walls of 'said' hollow resonant conducting member each of which i electrically connected to an opposite wall'of the hollow resonant conducting member next adjacent an aperture for deflecting the beam of electrons in its passage through the hollowconducting member, another portion-of the wall of the hollow resonant conducting membe having an aperture adapted to receive means for coupling the hollow conducting member to an input circuit, and-another portion of the wall of the hollow resonant conducting member having another aperture to receive a tuning plunger for controlling the resonant frequency of thehollow resonant conducting member, and tubular means extending'outwardly from the hollow conducting member aroundeach-of the last two mentioned apertures in the other walls of the hollow resonant conducting member.

3. Anelectron discharge device'having a cathode means for providing a beam of electrons and a collector for'receiving aid beam of electrons,

and means positioned between the cathode meansand collector and including a hollow resonant conducting member extending transversely of the path of the beam between the cathode means and the collector and having opposed apertures in oppositewallsthereof-through which the beam is directed during operation of said -electron discharge device, and a-pair ofinwardly directedrdefiectingelements each of which is-electrically connected to an opposite wall of the hollow resonant conducting member adjacent an aperture for deflecting the beam of electrons in its passage through the hollow resonant conducting member, the wall of the hollow resonant conducting member having other apertures positioned on opposite sides of said opposed apertures and adapted to receive means for coupling the hollow resonant conducting member to an input circuit, and to receive a tuning plunger for controlling the resonant frequency of the hollow resonant conducting member, and tubular means extending outwardly from the hollow resonant conducting member around said other apertures, and an apertured conducting element extending between the tubular means and having an aperture registering with the opposedapertures in said hollow resonant conducting member.

4. An electron discharge device having a cathode means for providing a beam of electrons and a collector for receiving said beam of electrons, and means positioned between the cathode means and collector and including a hollow resonant conducting member extending transversely of the path of the beam between the cathode means and the collector and having opposed apertures in opposite Walls thereof through which the beam is directed during operation of said electron discharge device, and inwardly directed deflecting elements electrically connected to the walls of the hollow resonant conducting member adjacent the cpposed apertures for deflecting the beam of electrons in its passage through the hollow conducting member, the wall of the hollow conducting member having other apertures positioned on opposite sides of said opposed apertures and adapted to receive means for coupling the hollow conducting member to an input circuit, and to receive a tuning plunger for controlling the resonant frequency of the hollow conducting member, and tubular means extend ing outwardly from the hollow conducting member around each of said other apertures, and an apertured conducting element extending between the tubular means and having an aperture registering with the opposed apertures in said resonant hollow conducting member, and a rod-like element extending across the aperture in the apertured conducting element providing a double aperture.

5. An electron discharge device having a cathode means for providing a beam of electrons and a collector for receiving said beam of electrons, and means positioned between the cathode means and collector and including a, resonant h'olloW conducting member extending transversely of the path of the beam between the cathode means and the collector and having opposed apertures in opposite walls thereof through which the beam is directed during operation of said electron discharge device, and inwardly directed deflecting elements electrically connected to the walls of the resonant hollow conducting member adjacent the apertures for deflecting the beam of electrons in its passage through the resonant hollow conducting member, the wall of the hollow conducting member having other apertures adapted to receive means for coupling the hollow conducting member to an input circuit and to receive a tuning plunger for controlling the resonant frequency of the hollow conducting member, and a conducting enclosure extending between the cathode means and the resonant hollow conducting member and having an apertured element extending transversely of the beam 'path,-the

aperture in said apertured element being aligned with the opposed apertures in the resonant hollow conducting member. 7 r

6. An electron discharge device having a cathode means for providing a beam of electrons and a collector for receiving said beam of electrons, and means positioned between the cathode means and collector and including a resonant hollow conducting member extending transversely of the path of the beam between the cathode means and the collector and having opposed apertures in opposite walls thereof through which the beam is directed during operation of said electron discharge device, and inwardly directed deflecting elements electrically connected to the walls of the resonant hollow conducting member adjacent the apertures for deflecting the beam of electrons in its passage through the resonant hollow conducting member, the wall of the hollow conducting member having other apertures adapted to receive means for coupling the hollow conducting member to an input circuit and to receive a tuning plunger for controlling the resonant frequency of the hollow conducting member, and a conducting enclosure extending between the oathode means and the resonant hollow conducting member and having an apertured element extending transversely of th beam path, the aperture in said apertured element being aligned with the opposed apertures in the resonant hollow conducting member, and beam directing elements in said enclosure extending transversely of the path of the beam on opposite sides of the beam path for directing the beam through the opposed apertures in the hollow conducting memberand between the deflecting elements.

7. An electron discharge device having a cathode and a beam forming and focusing element positioned next adjacent the cathode for providing a directed beam of electrons and a collector for receiving said electrons, and means positioned between the collector and the beam forming and focusing element, including a cavity resonator extending transversely of the beam path between the cathode and the collector, said cavity resonator being provided with oppositely disposed apertures through which the beam is directed during operation of said device, and deflecting elements electrically connected to and supported by the walls of and within the cavity resonator, and adjacent the apertures and between which the beam of electrons passes during operation of said electron discharge device to be deflected, said cavity resonator having a third aperture and an outwardly extending tubular extension surrounding said third aperture, said tubular extension and aperture being adapted to receive a coupling loop, said cavity resonator having a fourth aperture and an outwardly extending tubular extension surrounding said fourth aperture and adapted to receive a tuning plunger, a, tubular member extending between the cavity resonator and the beam forming element, and including a transverse element having an aperture aligned with the oppositely disposed apertures in-the cavity resonator, and beam directing elements positioned adjacent said transverse element and on oppo- 8.. An electron discharge device having a cathode and a beam. forming and focusing element positionednext adjacent. the cathode for providing a directed beam of electrons, and a collector for receiving said electrons, and means positioned between the collector and the beam forming and focusing element, including a cavity resonator extending transversely of the beam path between the. cathode and the collector, said cavity resonator being provided with. oppositely disposed apertures through which the beam is. directed during operation of said. electron. discharge device, anddeflecting elements, electrically connected to and supported by the walls of and within the cavity resonator and adjacent. the apertures and between which the beam of'electrons, passes during operation of said electron discharge device to be deflected, said cavity resonator having a third aperture and an outwardly extending tubular extension surrounding said third aperture, said tubular extension and aperture being adaptedto receive a coupling loop, said. cavity resonator having a fourth aperture and an outwardly extending tubular. extension. surrounding said fourth aperture and adapted to receive atuning plunger, a tubular member extending between the cavity resonator and. the beam forming and focusing element, and including a transverse element intermediate the ends of said tubular memher and having an aperture, aligned with the oppositely disposed apertures in the cavity resonator, and beam directing elements positioned adjacent said transverse element. and on opposite sides of the beam path for directing the beam through the oppositely disposed apertures in the cavity resonator, and an apertured conducting member extending between andsupported by said outwardly extending tubular extensions, th ap erture in said apertured conducting member being aligned with the apertures in'the cavity resi onator and registering with the collector, and a second transverse apertured element closing the end of the tubular member adjacentthe beam forming and focusing element.

9. An electron discharge device having an envelope containing cathode means for providing a beam of electrons and a collector, for receiving said beam of electrons, and means positioned between the cathode means and collector and including a resonant hollow conducting member. extending transversely of the path of the beam between the cathode and the collector and having opposed apertures in opposite walls thereof through which the beam is directed when said electron discharge device is in operation, andvinwardly directed deflecting elements positioned within but separate from the walls of. said resonant hollow conducting member and electrically connected to thewalls of the resonant hollow conducting member next adjacent the apertures for deflecting the beam of electrons in its passage through the resonant hollow conducting member, said resonant hollow conducting member. having other apertures adapted to receive means for coupling the resonant hollow conducting member to an input circuit and to receive a tuning plunger for controlling the resonant frequency of the resonant. hollow conducting member, said envelope having a reentrant portion extending through each of; the other apertures and. withinthe interior of the resonant hollow con-ducting member.

10. An electron discharge device having an envelope containing cathode means for providing a beam of electrons and a collector for receiving said beam of electrons, and means positioned between the cathode means and collector and. including a resonant hollow conductingmember extending transversely of the path of the beam between the cathode and the collector and having opposed, apertures in opposite walls thereof through which the beam is directed during operation of, said electron discharge device, and inwardly directed deflecting elements positioned within but separate from said resonant hollow conducting member and electrically connected to the walls oi'the resonant hollow conducting member next'adj'acent. the apertures for deflecting the beam. of'electrons in its passage through the resonant. hollow conducting member, said resonant hollow conducting member having other apertures adapted to receive means for coupling the resonant hollow conducting member to an input circuit and to receive a tuning plunger for controlling the. resonant frequency of the resonant hollow conducting member, and, tubular means extending outwardly from the. resonant hollow conducting member around the other. apertures i'n thev resonant hollow conducting member, said envelope having a reentrant portion extending through each of the tubular means into the interior of the resonant hollow'conducting member.

'11. An electron discharge device having a cathode means for supplying a directed beam of electrons, a first hollow resonant conducting member positioned'in the path of the beam and having a pair of aligned apertures in opposite walls. through which the beam of electrons is directed during, operation of said electron discharge device and a pair of inwardly extending deflecting elements within, said hollow resonant cavity member buir'separate from the walls thereof andeach ofjwhichis connected to an opposite wall of the, hollow resonant conducting member .next adjacent the aperture and between which elements the. beam is directed during operation .oi said. electron discharge device, and a second hollow resonant conducting member in the path oifsaidbeam and having an aperture aligned with the. apertures in the first hollow resonant conducting member and through which said beam can be directed during. operation. of said electron discharge devi'caand a conducting member positioned between the hollow resonant conducting members and having an aperture aligned with the apertures in the hollow resonant conducting members.

1'2. An electron discharge device having a cathode means for supplying a directed beam of electrons and a collector for receiving said electrons, and a first. resonant hollow conducting member positioned between the cathode means and collector and having a pair of aligned apertures in opposite walls through which the beam of electrons is directed during operation of said electron discharge device and a pair of'deflecting elements extending within and transversely of the walls of the resonant hollow conducting member and each of which. is connected to an opposite wall of the resonant hollow conducting member next adjacent the aperture and between. which elements the beam is directed during operation of said. device, and a second resonant hollow conducting member positioned between the first resonant hollow conducting member and said colcathode means for supplying a directed beam of electrons and a collector for receiving said electrons, and a first resonant hollow conducting member positioned between the cathode means and collector and having a pair oraligned apertures in opposite walls through which the beam of electrons is directed during operation of said electron discharge device and a pair of deflecting elements separate from and extending transversely of the walls of the resonant hollow conducting member and each of which is connected to an opposite wall of the resonant hollow conducting member adjacent the aperture and between which elements the beam is'directed during operation of said device, and a second resonant hollow conducting member positioned between the first resonant hollow conducting memher and said collector and having oppositely disposed apertures aligned with the apertures in the first resonant hollow conducting member, and a conducting plate member positioned between the resonant hollow conducting members and having an'aperture aligned with the apertures in the resonant hollow conducting members, said resonant hollow conducting members having other apertures, said other apertures being adapted to receive a coupling loop for driving the first resonant hollow conducting member and an output coupling loop for extracting energy from the second resonant hollow conducting member.

'14. An electron discharge device having an envelope containing at one end a cathode means for supplying a beam of electrons, and a collector for receiving said electrons, a pair of successive cavity resonators, each of which has oppositely disposed apertures through which the beam of electrons is directed during operation of said electron discharge device, the cavity resonator next adjacent the cathode having inwardly di-' rected deflecting elements separate from the walls of said last cavity resonator and connected to opposite walls next adjacent the apertures for periodically deflecting the beam of electrons, and a conducting member positioned between the' cavity resonators and having an aperture aligned with the apertures in the cavity resonators each of said cavity resonators being provided with an aperture in another portion of the wall of the cavity resonator, said envelope having a reentrant portion extending within each of 7 said last named apertures, each of said reentrant 7 portions being adapted to receive a coupling loop.

'15. An electron discharge device having a cathode for forming a beamof electrons and a collector for said electrons, and means positioned between the cathode and collector and including a resonant hollow conducting member having aligned apertures in opposite walls thereof and through which the electron beam is to be directed, and a pair of deflecting elements within said resonant hollow conducting member, each electrically connected to an opposite wall of the resonant hollow conducting member and positioned adjacent an aperture, said resonant hollow conducting member comprising a pair of electrically insulated portions each of which includes one wall supporting a deflecting element.

16. An electron discharge device having a cath- V ode for forming a beam of electrons and a lector ,for said electrons, and means positioned between the cathode and collector and including a resonant hollow conducting member having aligned apertures in opposite walls thereof and through which the electron beam is directed during operation of said electron discharge device, and a pair of deflecting elements within said resonant hollow conducting member, each electrically connected to an opposite wall of the resonant hollow conducting member andpositioned adjacent an aperture, said resonant hollowconducting member comprising two electrically insulated portions, each of which includes one wall supporting a deflecting element, and an apertured plate positioned between the resonant hollow conducting member and the collector and across which the electron beam is deflected during operation of the device, the aperture in said apertured plate registering with the apertures in said resonant hollow conducting member.

17. An electron discharge device having a cathode for forming a beam of electrons and a collector for said electrons, and means positioned between the cathode and collector and including a resonant hollow conducting member having aligned apertures in opposite walls thereof and through which the electron beam is directed during operation of said electron discharge device, and a pair of inwardly directed deflecting elements each supported by an opposite wall of the resonant hollow conducting member and positioned adjacent the apertures, said resonant hollow conducting member comprising two electrically insulated portions, and a conducting enclosing member extending between the cathode and the resonant hollow conducting member and having a transverse apertured element with the aperture in alignment with the apertures in the resonant hollow conducting member, and an apertured plate positioned between the resonant hollow conducting member and the collector and across which the electron beam is deflected during operation of the device. Y

18. An electron discharge device having a cathode means for supplying a directed beam of electrons, a first hollow resonant conducting member positioned in the path of the beam and having a pair of aligned apertures in opposite walls through which the beam of electrons is directed during operation of said electron discharge device, and a pair of inwardly extending elements separate from and transverse to the walls of said first hollow resonant conducting member and each of which is connected to an opposite wall of the hollow resonant conducting member adjacent an aperture and between which elements the beam is directed during operation of said electron discharge device, and' a second hollow resonant conducting member in the path of said beam and having an aperture aligned with the apertures in the first hollow resonant conducting member and through which said beam of electrons can be directed. V

19. An electron discharge device having a cathode means for supplying a directed beam of electrons, a first hollow resonant conducting member positioned in the path of the beam and having aperture and. between which elements the beam is to be directed, and a second hollow resonant conducting member in the path of said beam and having an aperture ali ned with the apertures in the first hollow resonant conducting member, each of said hollow resonant conducting members being provided with another aperture and coupling means extending between said ho1 10w resonant conducting members and through the last mentioned apertures for transferring energy between said hollow resonant conducting members.

' GEORGE ROSS KILGORE.

LOUIS MALTER. 

